Merge lp:~jamesodhunt/ubiquity/bug-944191 into lp:ubiquity

[James Hunt]

  * scripts/install.py: Ignore mkdir failure if directory does (now)
    exist to accommodate update-apt-cache running in parallel with
    copy_all() (LP: #944191).

[Colin Watson (cjwatson)]

The style in ubiquity is to check specifically for OSError, rather than for the more general EnvironmentError. Doing so is safe in this case; you aren't going to get anything else from os.mkdir.

I don't think you need to recheck os.path.isdir; simply having got EEXIST from os.mkdir implies that. I would just write this as 'if e.errno != errno.EEXIST'.

review: Needs Fixing

[lp:~jamesodhunt/ubiquity/bug-944191]

5282. By James Hunt on 2012-03-20

scripts/install.py: Ignore mkdir failure if directory does (now)
exist to accommodate update-apt-cache running in parallel with
copy_all() (LP: #944191).

[Evan (ev)]

Make sure you have:

DEBCHANGE_RELEASE_HEURISTIC=changelog
DEBCHANGE_MULTIMAINT_MERGE=yes

in ~/.devscripts so that dch -U does the right thing.

Unmerged revisions

=== modified file 'debian/changelog'
--- debian/changelog	2012-03-20 13:29:02 +0000
+++ debian/changelog	2012-03-20 15:36:22 +0000
@@ -1,9 +1,15 @@
-ubiquity (2.9.31) UNRELEASED; urgency=low
+ubiquity (2.9.31ubuntu1) UNRELEASED; urgency=low
 
+  [ Colin Watson ]
   * Fix misc.set_indicator_keymaps to handle ll_CC forms of lang, and also
     to avoid crashing on unknown languages in general (LP: #960047).
 
- -- Colin Watson <[e-mail]>  Tue, 20 Mar 2012 13:28:02 +0000
+  [ James Hunt ]
+  * scripts/install.py: Ignore mkdir failure if directory does (now)
+    exist to accommodate update-apt-cache running in parallel with
+    copy_all() (LP: #944191).
+
+ -- James Hunt <[e-mail]>  Tue, 20 Mar 2012 14:26:00 +0000
 
 ubiquity (2.9.30) precise; urgency=low
 

=== modified file 'scripts/install.py'
--- scripts/install.py	2012-02-16 02:47:22 +0000
+++ scripts/install.py	2012-03-20 15:36:22 +0000
@@ -423,7 +423,16 @@
                     os.symlink(linkto, targetpath)
                 elif stat.S_ISDIR(st.st_mode):
                     if not os.path.isdir(targetpath):
-                        os.mkdir(targetpath, mode)
+                        try:
+                            os.mkdir(targetpath, mode)
+                        except EnvironmentError, e:
+                            # there is a small window where update-apt-cache
+                            # can race with us since it creates
+                            # "/target/var/cache/apt/...". Hence, ignore
+                            # failure if the directory does now exist where
+                            # brief moments before it didn't.
+                            if not (e.errno == errno.EEXIST and os.path.isdir(targetpath)):
+                                raise
                 elif stat.S_ISCHR(st.st_mode):
                     os.mknod(targetpath, stat.S_IFCHR | mode, st.st_rdev)
                 elif stat.S_ISBLK(st.st_mode):